Experimental and numerical study of error fields in the CNT stellarator

被引：18

作者：

Hammond, K. C. ^{[1
]}

Anichowski, A. ^{[1
]}

Brenner, P. W. ^{[1
]}

Pedersen, T. S. ^{[1
,3
]}

Raftopoulos, S. ^{[2
]}

Traverso, P. ^{[1
,4
]}

Volpe, F. A. ^{[1
]}

机构：

[1] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA

[2] Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA

[3] Max Planck Inst Plasma Phys, D-17491 Greifswald, Germany

[4] Auburn Univ, Dept Phys, Auburn, AL 36849 USA

来源：

PLASMA PHYSICS AND CONTROLLED FUSION | 2016年 / 58卷 / 07期

基金：

美国国家科学基金会;

关键词：

error field; stellarator; CNT; optimization; RECONSTRUCTION; DESIGN; COILS;

D O I：

10.1088/0741-3335/58/7/074002

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

Sources of error fields were indirectly inferred in a stellarator by reconciling computed and numerical flux surfaces. Sources considered so far include the displacements and tilts of the four circular coils featured in the simple CNT stellarator. The flux surfaces were measured by means of an electron beam and fluorescent rod, and were computed by means of a Biot-Savart field-line tracing code. If the ideal coil locations and orientations are used in the computation, agreement with measurements is poor. Discrepancies are ascribed to errors in the positioning and orientation of the in-vessel interlocked coils. To that end, an iterative numerical method was developed. A Newton-Raphson algorithm searches for the coils' displacements and tilts that minimize the discrepancy between the measured and computed flux surfaces. This method was verified by misplacing and tilting the coils in a numerical model of CNT, calculating the flux surfaces that they generated, and testing the algorithm's ability to deduce the coils' displacements and tilts. Subsequently, the numerical method was applied to the experimental data, arriving at a set of coil displacements whose resulting field errors exhibited significantly improved agreement with the experimental results.

引用

页数：13

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